File: | src/lib/libelf/libelf_ehdr.c |
Warning: | line 76, column 7 Although the value stored to 'shtype' is used in the enclosing expression, the value is never actually read from 'shtype' |
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1 | /*- |
2 | * Copyright (c) 2006,2008 Joseph Koshy |
3 | * All rights reserved. |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
8 | * 1. Redistributions of source code must retain the above copyright |
9 | * notice, this list of conditions and the following disclaimer. |
10 | * 2. Redistributions in binary form must reproduce the above copyright |
11 | * notice, this list of conditions and the following disclaimer in the |
12 | * documentation and/or other materials provided with the distribution. |
13 | * |
14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
15 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
16 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
17 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
18 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
19 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
20 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
21 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
22 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
23 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
24 | * SUCH DAMAGE. |
25 | */ |
26 | |
27 | #include <assert.h> |
28 | #include <gelf.h> |
29 | #include <libelf.h> |
30 | #include <stdlib.h> |
31 | |
32 | #include "_libelf.h" |
33 | |
34 | ELFTC_VCSID("$Id: libelf_ehdr.c,v 1.3 2020/05/18 06:46:23 jsg Exp $")__asm__(".ident\t\"" "$Id: libelf_ehdr.c,v 1.3 2020/05/18 06:46:23 jsg Exp $" "\""); |
35 | |
36 | /* |
37 | * Retrieve counts for sections, phdrs and the section string table index |
38 | * from section header #0 of the ELF object. |
39 | */ |
40 | static int |
41 | _libelf_load_extended(Elf *e, int ec, uint64_t shoff, uint16_t phnum, |
42 | uint16_t strndx) |
43 | { |
44 | size_t fsz; |
45 | Elf_Scn *scn; |
46 | uint32_t shtype; |
47 | _libelf_translator_function *xlator; |
48 | |
49 | assert(STAILQ_EMPTY(&e->e_u.e_elf.e_scn))(((((&e->e_u.e_elf.e_scn)->stqh_first) == ((void *) 0))) ? (void)0 : __assert2("/usr/src/lib/libelf/libelf_ehdr.c" , 49, __func__, "STAILQ_EMPTY(&e->e_u.e_elf.e_scn)")); |
50 | |
51 | fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, 1); |
52 | assert(fsz > 0)((fsz > 0) ? (void)0 : __assert2("/usr/src/lib/libelf/libelf_ehdr.c" , 52, __func__, "fsz > 0")); |
53 | |
54 | if (shoff + fsz < shoff) { /* Numeric overflow. */ |
55 | LIBELF_SET_ERROR(HEADER, 0)do { (_libelf.libelf_error) = (((ELF_E_HEADER) & 0xFF) | ( ((0)) << 8)); } while (0); |
56 | return (0); |
57 | } |
58 | |
59 | if ((uint64_t) e->e_rawsize < shoff + fsz) { |
60 | LIBELF_SET_ERROR(HEADER, 0)do { (_libelf.libelf_error) = (((ELF_E_HEADER) & 0xFF) | ( ((0)) << 8)); } while (0); |
61 | return (0); |
62 | } |
63 | |
64 | if ((scn = _libelf_allocate_scn(e, (size_t) 0)) == NULL((void *)0)) |
65 | return (0); |
66 | |
67 | xlator = _libelf_get_translator(ELF_T_SHDR, ELF_TOMEMORY, ec, |
68 | _libelf_elfmachine(e)); |
69 | (*xlator)((unsigned char *) &scn->s_shdr, sizeof(scn->s_shdr), |
70 | (unsigned char *) e->e_rawfile + shoff, (size_t) 1, |
71 | e->e_byteorder != LIBELF_PRIVATE(byteorder)(_libelf.libelf_byteorder)); |
72 | |
73 | #define GET_SHDR_MEMBER(M) ((ec == ELFCLASS321) ? scn->s_shdr.s_shdr32.M : \ |
74 | scn->s_shdr.s_shdr64.M) |
75 | |
76 | if ((shtype = GET_SHDR_MEMBER(sh_type)) != SHT_NULL0) { |
Although the value stored to 'shtype' is used in the enclosing expression, the value is never actually read from 'shtype' | |
77 | LIBELF_SET_ERROR(SECTION, 0)do { (_libelf.libelf_error) = (((ELF_E_SECTION) & 0xFF) | (((0)) << 8)); } while (0); |
78 | return (0); |
79 | } |
80 | |
81 | e->e_u.e_elf.e_nscn = (size_t) GET_SHDR_MEMBER(sh_size); |
82 | e->e_u.e_elf.e_nphdr = (phnum != PN_XNUM0xffff) ? phnum : |
83 | GET_SHDR_MEMBER(sh_info); |
84 | e->e_u.e_elf.e_strndx = (strndx != SHN_XINDEX0xffff) ? strndx : |
85 | GET_SHDR_MEMBER(sh_link); |
86 | #undef GET_SHDR_MEMBER |
87 | |
88 | return (1); |
89 | } |
90 | |
91 | #define EHDR_INIT(E,SZ)do { ElfSZ_Ehdr *eh = (E); eh->e_ident[0] = 0x7f; eh->e_ident [1] = 'E'; eh->e_ident[2] = 'L'; eh->e_ident[3] = 'F'; eh ->e_ident[4] = ELFCLASSSZ; eh->e_ident[5] = 0; eh->e_ident [6] = (_libelf.libelf_version) & 0xFFU; eh->e_machine = 0; eh->e_type = ELF_K_NONE; eh->e_version = (_libelf.libelf_version ); } while (0) do { \ |
92 | Elf##SZ##_Ehdr *eh = (E); \ |
93 | eh->e_ident[EI_MAG00] = ELFMAG00x7f; \ |
94 | eh->e_ident[EI_MAG11] = ELFMAG1'E'; \ |
95 | eh->e_ident[EI_MAG22] = ELFMAG2'L'; \ |
96 | eh->e_ident[EI_MAG33] = ELFMAG3'F'; \ |
97 | eh->e_ident[EI_CLASS4] = ELFCLASS2##SZ; \ |
98 | eh->e_ident[EI_DATA5] = ELFDATANONE0; \ |
99 | eh->e_ident[EI_VERSION6] = LIBELF_PRIVATE(version)(_libelf.libelf_version) & 0xFFU; \ |
100 | eh->e_machine = EM_NONE0; \ |
101 | eh->e_type = ELF_K_NONE; \ |
102 | eh->e_version = LIBELF_PRIVATE(version)(_libelf.libelf_version); \ |
103 | } while (0) |
104 | |
105 | void * |
106 | _libelf_ehdr(Elf *e, int ec, int allocate) |
107 | { |
108 | void *ehdr; |
109 | size_t fsz, msz; |
110 | uint16_t phnum, shnum, strndx; |
111 | uint64_t shoff; |
112 | int (*xlator)(unsigned char *_d, size_t _dsz, unsigned char *_s, |
113 | size_t _c, int _swap); |
114 | |
115 | assert(ec == ELFCLASS32 || ec == ELFCLASS64)((ec == 1 || ec == 2) ? (void)0 : __assert2("/usr/src/lib/libelf/libelf_ehdr.c" , 115, __func__, "ec == ELFCLASS32 || ec == ELFCLASS64")); |
116 | |
117 | if (e == NULL((void *)0) || e->e_kind != ELF_K_ELF) { |
118 | LIBELF_SET_ERROR(ARGUMENT, 0)do { (_libelf.libelf_error) = (((ELF_E_ARGUMENT) & 0xFF) | (((0)) << 8)); } while (0); |
119 | return (NULL((void *)0)); |
120 | } |
121 | |
122 | if (e->e_class != ELFCLASSNONE0 && e->e_class != ec) { |
123 | LIBELF_SET_ERROR(CLASS, 0)do { (_libelf.libelf_error) = (((ELF_E_CLASS) & 0xFF) | ( ((0)) << 8)); } while (0); |
124 | return (NULL((void *)0)); |
125 | } |
126 | |
127 | if (e->e_version != EV_CURRENT1) { |
128 | LIBELF_SET_ERROR(VERSION, 0)do { (_libelf.libelf_error) = (((ELF_E_VERSION) & 0xFF) | (((0)) << 8)); } while (0); |
129 | return (NULL((void *)0)); |
130 | } |
131 | |
132 | if (e->e_class == ELFCLASSNONE0) |
133 | e->e_class = ec; |
134 | |
135 | if (ec == ELFCLASS321) |
136 | ehdr = (void *) e->e_u.e_elf.e_ehdr.e_ehdr32; |
137 | else |
138 | ehdr = (void *) e->e_u.e_elf.e_ehdr.e_ehdr64; |
139 | |
140 | if (ehdr != NULL((void *)0)) /* already have a translated ehdr */ |
141 | return (ehdr); |
142 | |
143 | fsz = _libelf_fsize(ELF_T_EHDR, ec, e->e_version, (size_t) 1); |
144 | assert(fsz > 0)((fsz > 0) ? (void)0 : __assert2("/usr/src/lib/libelf/libelf_ehdr.c" , 144, __func__, "fsz > 0")); |
145 | |
146 | if (e->e_cmd != ELF_C_WRITE && e->e_rawsize < (off_t) fsz) { |
147 | LIBELF_SET_ERROR(HEADER, 0)do { (_libelf.libelf_error) = (((ELF_E_HEADER) & 0xFF) | ( ((0)) << 8)); } while (0); |
148 | return (NULL((void *)0)); |
149 | } |
150 | |
151 | if ((msz = _libelf_msize(ELF_T_EHDR, ec, EV_CURRENT1)) == 0) |
152 | return (NULL((void *)0)); |
153 | |
154 | if ((ehdr = calloc((size_t) 1, msz)) == NULL((void *)0)) { |
155 | LIBELF_SET_ERROR(RESOURCE, 0)do { (_libelf.libelf_error) = (((ELF_E_RESOURCE) & 0xFF) | (((0)) << 8)); } while (0); |
156 | return (NULL((void *)0)); |
157 | } |
158 | |
159 | if (ec == ELFCLASS321) { |
160 | e->e_u.e_elf.e_ehdr.e_ehdr32 = ehdr; |
161 | EHDR_INIT(ehdr,32)do { Elf32_Ehdr *eh = (ehdr); eh->e_ident[0] = 0x7f; eh-> e_ident[1] = 'E'; eh->e_ident[2] = 'L'; eh->e_ident[3] = 'F'; eh->e_ident[4] = 1; eh->e_ident[5] = 0; eh->e_ident [6] = (_libelf.libelf_version) & 0xFFU; eh->e_machine = 0; eh->e_type = ELF_K_NONE; eh->e_version = (_libelf.libelf_version ); } while (0); |
162 | } else { |
163 | e->e_u.e_elf.e_ehdr.e_ehdr64 = ehdr; |
164 | EHDR_INIT(ehdr,64)do { Elf64_Ehdr *eh = (ehdr); eh->e_ident[0] = 0x7f; eh-> e_ident[1] = 'E'; eh->e_ident[2] = 'L'; eh->e_ident[3] = 'F'; eh->e_ident[4] = 2; eh->e_ident[5] = 0; eh->e_ident [6] = (_libelf.libelf_version) & 0xFFU; eh->e_machine = 0; eh->e_type = ELF_K_NONE; eh->e_version = (_libelf.libelf_version ); } while (0); |
165 | } |
166 | |
167 | if (allocate) |
168 | e->e_flags |= ELF_F_DIRTY0x002U; |
169 | |
170 | if (e->e_cmd == ELF_C_WRITE) |
171 | return (ehdr); |
172 | |
173 | xlator = _libelf_get_translator(ELF_T_EHDR, ELF_TOMEMORY, ec, |
174 | _libelf_elfmachine(e)); |
175 | (*xlator)((unsigned char*) ehdr, msz, e->e_rawfile, (size_t) 1, |
176 | e->e_byteorder != LIBELF_PRIVATE(byteorder)(_libelf.libelf_byteorder)); |
177 | |
178 | if (ec == ELFCLASS321) { |
179 | phnum = ((Elf32_Ehdr *) ehdr)->e_phnum; |
180 | shnum = ((Elf32_Ehdr *) ehdr)->e_shnum; |
181 | shoff = ((Elf32_Ehdr *) ehdr)->e_shoff; |
182 | strndx = ((Elf32_Ehdr *) ehdr)->e_shstrndx; |
183 | } else { |
184 | phnum = ((Elf64_Ehdr *) ehdr)->e_phnum; |
185 | shnum = ((Elf64_Ehdr *) ehdr)->e_shnum; |
186 | shoff = ((Elf64_Ehdr *) ehdr)->e_shoff; |
187 | strndx = ((Elf64_Ehdr *) ehdr)->e_shstrndx; |
188 | } |
189 | |
190 | if (shnum >= SHN_LORESERVE0xff00 || |
191 | (shoff == 0LL && (shnum != 0 || phnum == PN_XNUM0xffff || |
192 | strndx == SHN_XINDEX0xffff))) { |
193 | LIBELF_SET_ERROR(HEADER, 0)do { (_libelf.libelf_error) = (((ELF_E_HEADER) & 0xFF) | ( ((0)) << 8)); } while (0); |
194 | return (NULL((void *)0)); |
195 | } |
196 | |
197 | /* |
198 | * If extended numbering is being used, read the correct |
199 | * number of sections and program header entries. |
200 | */ |
201 | if ((shnum == 0 && shoff != 0) || phnum == PN_XNUM0xffff || strndx == SHN_XINDEX0xffff) { |
202 | if (_libelf_load_extended(e, ec, shoff, phnum, strndx) == 0) |
203 | return (NULL((void *)0)); |
204 | } else { |
205 | /* not using extended numbering */ |
206 | e->e_u.e_elf.e_nphdr = phnum; |
207 | e->e_u.e_elf.e_nscn = shnum; |
208 | e->e_u.e_elf.e_strndx = strndx; |
209 | } |
210 | |
211 | return (ehdr); |
212 | } |